DESCRIPTION: The long term goal of this program is to relate protein structure and dynamics to function. There are two principal objectives in this competing renewal. The first objective centers on the demonstration that fluorescence anisotropy decays can be used to detect conformational substates. The achievement of this particular goal will require the development of improved methods of analysis of anisotropy data, especially for detection and quantification of picosecond correlation times; development of alternate interpretative models and procedures; creation of optimal protein models bearing single fluorphors; and using molecular dynamics/mechanics simulations to assess the molecular motions predicted by analysis of anisotropy data. The second major objective focuses on the evaluation of properties of water in the lipid binding cavity of intestinal fatty acid binding protein. This cavity and the water within will be characterized by X-filtered NOESY and ROESY NMR measurements and by nuclear magnetic relaxation dispersion techniques; molecular dynamics and electrostatic calculations; structural analysis of IFABP-fluorophor complexes and covalent adducts and their comparison to obtained fluorescence measurements of dipolar relaxation rates.